The Locate and Detain List of the Empire, a so-called "temporary" security protocol, was just one of numerous such measures put into effect by Palpatine, the Emperor. It provided a task for novice COMPNOR agents, keeping them busy responding to reports from citizens who were informing on their neighbors as potential Rebels, instead of interfering with the Emperor's carefully orchestrated plans.
Following the Emperor's demise, the Locate and Detain List evolved into a kind of "to-do" item compilation for assassins and bounty hunters. A hunter with adequate skills could amass a considerable amount of wealth – perhaps even more – by successfully apprehending a Rebel whose name appeared on the list.
Gunner Groth possessed a version of the list and attempted to seize Mara Jade, who had recently been added to it. Regrettably for Groth, his skill level proved inadequate for the challenge, and he perished during the confrontation.